Electrical tell tale system for trailers

ABSTRACT

An electrical tell tale system for trailers that consists of a unique tell tale monitor which is light weight which houses different colored light emitting diodes which define each individual trailer circuit. The tell tale monitor has an attached modular cable and modular plug which is connected by a modular socket to the main control unit. The main control unit has two protruding leads which are connected in series with the vehicles trailer wiring harness by connectors. The system works by scanning the trailer signals passing through the main control unit and specially set, wound resistive current sensing coils, which close a reed switch at the correct current which in turn sends a low voltage signal through the modular connection and through the modular cable to the tell tale monitor which will illuminate a certain light emitting diode to notify if the trailer circuit is operational. If the trailer circuit passing through the main control unit is in-operational, the unit on the tell tale monitor will not light, indicating a fault. If a wrong globe is installed for a particular trailer circuit the light emitting diode on the monitor will flash, also indicating a fault The system is tested by unique current and voltage testing tools.

INTRODUCTION TO THE INVENTION

When any road registered vehicle is hauling any road registered trailer,it is a critical fact of law and safety that the trailer which thevehicle is hauling must have directional and signal electric lighting tocommunicate the drivers intentions to the external environment aroundthe vehicle. It is even more critical that these trailer lightingsystems work and comply in every way to road standards thus meeting theroads and traffic authorities legal requirements. If the legal signallighting on any road registered trailer is not within compulsoryspecifications, it is breaking the law. If this vehicle was to beinvolved in an accident both legal and insurance issues would be of anegative consequence.

Therefore ensuring operation of trailer lamps and their circuits becomesan important issue. Commonly a driver will go to the rear of the trailerto see if the lights are working before they start their journey. Thismethod of checking trailer lights is not practicable whilst the vehicleis in motion. Various fault indicator systems for trailers have beendeveloped for fault detection of trailer circuits, however allforgetting to address simplicity and unity in areas such as installationand operation.

At present there is no universal device which has the ability to bemounted in any vehicle which has a trailer connector and serve thefunction of warning the driver of the vehicle if all and any trailercircuits such as stop lights, tail or clearance lights, directionalindicator lights and units such as electric brake systems, are workingcorrectly or not working correctly whilst the driver is still seated inthe driver-seat-and the vehicle in motion or stationary. The Inventiondocumented within is a universal electrical tell tale system fortrailers which can be mounted in any vehicle anywhere in the world. Themain goal and purpose is to automatically warn the driver of a vehiclethat is hauling a trailer, by means of a unique tell tale monitorwhether the vehicle be in motion or stationary, that electrical circuitson the trailer are correctly working or malfunctioning when thosetrailer signals are used.

SUMMARY OF THE INVENTION

The invented system consists of two main units and their electricalconnections which can be simply and universally mounted in any vehiclewhich is equipped with a electrical trailer connection plug. One mainunit being a main control unit, situated at the rear of the vehicle,which is connected in series with the vehicle's trailer plug wiring. Thesecond main unit being a tell tale monitor consisting of differentcoloured light emitting diodes, each for a different trailer circuit.The tell tale monitor is mounted so the driver of the vehicle hasvisible access to it and is connected to the main control unit by a thinmodular, low voltage cable. The two units, their mounting and connectionin the vehicle form an electrical tell tale system which by means of auniversally mounted tell tale monitor, using light or sound thatautomatically convey the operating condition of trailer circuits to thedriver when those trailer circuits are used. The tell tale system wheninstalled in the vehicle can be tested, by designed testing tools whichtest systems operation by current and voltage tests.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three dimensional pictorial view of the electrical tell talesystem showing all main components.

FIG. 2 is a detailed schematic circuit diagram of the electrical telltale system which shows all main components and all detailed componentsand shows how the heart of the system operates.

FIG. 3 to FIG. 14 are operating examples of how the system works withdifferent trailer circuits and circuit conditions.

FIG. 15 shows the mounting of the main control unit, the mounting of thetell tale monitor and their connections to the vehicles wiring loom.

FIG. 16 shows how the system conveys the operational trailer circuit tothe driver and also indicates mounting of the system.

FIG. 17 is a three dimensional pictorial view of the load testing unitfor the tell tale system.

FIG. 18 is a three dimensional pictorial view of the seven pin flat typevoltage tester for the tell tale system.

FIG. 19 is a three dimensional pictorial view of the large seven pinround type voltage tester for the tell tale system.

FIG. 20 is a three dimensional pictorial view of the small seven pinround type voltage tester for the tell tale system.

FIG. 21a is a circuit schematic of the load tester and voltage testerconnected together showing all components.

FIG. 21b is a circuit schematic of the voltage testing unit showing thebuzzer version of the tester.

FIG. 22a is a top view of seven pin flat type voltage testing unit.

FIG. 22b is the standard rear connection plug for seven pin flat typevoltage testing unit.

FIG. 22c is the standard front connection plug for seven pin flat typevoltage testing unit.

FIG. 23a is a top view of the large seven pin round type voltage testingunit.

FIG. 23b is the standard rear connection plug for the large seven pinround voltage testing unit.

FIG. 23c is the standard front connection plug for the large seven pinround voltage testing unit.

FIG. 24a is the top view of the small seven pin round voltage testingunit.

FIG. 24b is the standard rear connection plug for the small seven pinround voltage testing unit.

FIG. 24c is the standard front connection plug for the small seven pinround voltage testing unit.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, the major parts of the system can be seen. Thetell tale monitor 1, is a small slim line plastic housing which has fourcoloured light emitting diodes (LEDs) 2,3,4 and 5 housed in its face. Amodular cable 6, is attached to the monitor to provide a signal sourceand return for the LEDs. Each LED 2 to 5, is a different colour and eachcolour of the LED represents different trailer circuits. 2 is a blue LEDfor electric brakes, 3 is a red LED for brakes, 4 is a yellow LED forparking lights 5 is a green LED for right and left turn indicators. Thetell tale monitor 1, can have more or less LEDs depending on how manycircuits there are to be monitored, however the standard coloring forthe main circuits stated is as above. The tell tale monitor 1, isconnected to the main control unit 10, by a modular cable 6 and modularconnection plug and modular socket 8 and 9.

The main control unit 10 is an epoxy filled plastic housing which holdsthe main circuitry of the system. The housing has two leads coming outeither side 7 and 12. Items 7 and 12 are seven core sheathed 4 mmcabling which the seven cores are distributed into connectors 11 and 13.These connectors 11 and 13, connect to the vehicles trailer wiringharness thuse connecting the main control unit 10 to the vehicle. 11 and13, can be either universal fitting electrical connector blocks in whichslight modification of the vehicles wiring loom is made for the unit tobe installed connectors 11 and 13 can also be original equipmentmanufacturer connector blocks so that the unit will plug straight intothe vehicles loom without any modification to the wiring.

The main control unit 10 scans the electrical signal passing through itgoing to the trailer and if that signal is correct, the main controlunit 10 will then send a signal through the modular connection 8 and 9through the modular cable 6 to illuminate LEDs 2 to 5 to indicate thatthose trailer circuits are operational when they are being used. If thetrailer signal the main control unit 10 scans is incorrect, no LEDs 2 to5 will light on the tell tale monitor 1.

With reference to FIG. 2a description of system components is asfollows. The main control unit 25 is connected in series with thevehicles trailer plug wiring via connectors 32 and 39. In this figureconnector 32 is the connection of the vehicles trailer signals IN fromthe vehicle and connector 39 is the connection of the vehicles signalsOUT to the trailer. The unit however can be connected reverse withoutaffecting the operation of the system in any way eg 39 could be signalIN and 32 signals OUT. The Tell Tale monitor 14, its earth return 15 andLED's 16,17,18 and 19 are electrically connected to the main controlunit 25 via five core modular cable 23 and modular connection 24. 26 to30 are the electrical circuits from the vehicle going into the maincontrol unit 25. 26 is the right turn signal, 27 is the left turnsignal, 28 is park light signal, 29 is brake signal and 30 is theelectric brake signal. 34 to 38 are electrical circuits coming out ofthe main control unit 25 and going to the various trailer circuits 60 to64. Each signal in corresponds to the signal out, thus 38 is the rightturn signal to the trailer, 37 is the left turn signal to the trailer,36 is the park light signal to the trailer, 35 is the brake signal tothe trailer and 34 is the electric brake signal to the trailer. 60 isthe right turn light, 61 is the left turn light 62, is the trailers parklights 63, is the trailers brake lights and 64 is the electric brakeactuator of the trailer. 33 is the trailers earth return and 31 is thevehicles earth return.

40 to 44 and 45 to 49 together make up the current sensing switch whichis a major component of the systems operation. The main circuitry of thecurrent sensing switch 40, 41, 42, 43 and 44 are connected in seriesbetween each in and out signal wiring within the main control unit 25.The circuitry of the current sensing switch, 40 to 44 are set speciallyfor each individual trailer circuit 60 to 64 circuit which ensurecorrectness of the system under operating conditions. 45 to 49 are thecontacts of the current sensing switches, which are closed by thecurrent sensing circuitry 40 to 44 when a particular trailer circuit 60to 64 is operational.

The current sensing circuitry 40 to 44 and the switch contacts 45 to 49consists of a copper wound coil and reed switch in order to close theswitch contacts 45 to 49. The current sensing circuitry 40 to 44 canclose the switch contacts 45 to 49 magnetically, by means of a customwound current sensing coil which consist of different wire sizes and areindividually wound for each trailer circuit, and the switch contacts 45to 49 being of a reed type. Thus the correct amount of magnetic fluxwill close the reed switch. 50 to 54 are suitable resistors to reducethe voltage going to the LED's 16 to 19 of the tell tale monitor 14.This also provides a safe level of current travelling through themodular cable 23 through the vehicle to the tell tale monitor 14. 55 to59 are the power connections for the current sensing switch contacts 45to 49. 66 is the earth connection for the tell tale monitor 14. 67 isthe earth of the vehicle

Thus the circuits going to the tell tale monitor 14 to light the LEDs 16to 19 are completed by means of either an magnetic or electronic currentsensing switch 40 to 44 and 45 to 49, which will cause the circuit toclose when a predetermined setting is reached. The system monitorscircuits when they are being used. The system will monitor all circuits60 to 64 at once if all circuits are being used. The system reports thetrailer circuits 60 to 64 operation by the tell tale monitor 14 in whichthe LEDs 16 to 19 will illuminate when the trailer circuits 60 to 64that are being used are operational. The LED's 16 to 19 of the tell talemonitor 14 will not illuminate if a the trailer circuits 60 to 64 beingused are not operating correctly. The current sensing switches 40 to 44also have the ability to detect the wrong globe in a trailer lightingcircuit, if the globe is of an incorrect current draw the currentsensing switch will cause the reed switch to chatter, causing theparticular light emitting diode 16 to 19 to flash on the tell talemonitor 14.

An description example is as follows. If the right turn indicator isactivated, current will flow from 26, through the current sensingcircuitry 40 and to the trailer wiring 38 and indicator globe 60 andthen to the earth return 33. As this current flows though the currentsensing circuitry 40 the circuitry generates a condition to close theswitch 49, current will then flow through connection point 55, throughthe closed switch 49 through resistor 50 through the modular connector24 and through the wire of the modular cable 23 to the tell tale monitor14 to light the LED 19. This will indicate to the driver of the vehiclethat the flasher circuit of the trailer is operating correctly. Ofcourse as the flasher circuit is not constant, the LED 19 on the telltale monitor 14 will flash in sequence with the vehicles flashing rate.If the flasher globe 60 is faulty or there is an open circuit in theline, no current will flow though the circuit, thus the current sensingcircuitry 40 will not generate a condition to close the switch contacts49 giving no current flow thus no illumination to LED 19. By LED 19 notilluminating, it warns the driver that a fault has occurred in the rightturn circuit 60 of the trailer. The main control unit 25 monitors alltrailer circuits 60 to 64 the same way as described above and reports bythe LEDs 16 to 19 Illuminating for and operational circuit or notilluminating, indicating a malfunctioning trailer circuit.

The modular socket 24 of the main control unit allows different telltale monitors to be connected to the main control unit 25. Differenttypes of monitors can be of such nature as FIG. 2b where a buzzer 21 isconnected in the earth return wiring 22. Thus this tell tale monitor 20warns the driver of the trailer circuits condition by light and sound.

FIGS. 3 to 14 show operating conditions of the tell tale system. Whenfitted to a vehicle. In FIG. 3, the hauling vehicle 67 has all circuitsoperational. The hauled trailer 68 also has all lights operational. Itcan be seen that the tell tale monitor 69 has all LED's illuminatedindicating all circuits are operating on the trailer. In FIG. 4 thehauling vehicle 70 has all circuits operational. The hauled trailer 71has no circuits operational. The tell tale monitor 72 has no LED'silluminated indicating that all trailer circuits are malfunctioning.FIG. 5 shows the hauling vehicle 73 with the hazard circuit operating.The hauled trailer also has the hazard circuit operating, The tell talemonitor 75 has the green turn LED illuminated indicating that thecircuit is functioning on the trailer. The hauling vehicle in 76 in FIG.6 also has the hazard signal on however the hauled trailer 77 has amalfunctioning hazard circuit and thus the green turn LED on the telltale monitor 78 is not illuminated. FIG. 7 shows the hauling vehicle 79with the turn indicator on, and the hauled trailer 80 has the also hasthe turn indicator working, the tell tale monitor 81 is indicating thisis the case by having the green turn LED illuminated. FIG. 8 now showsthe hauling vehicle 82 with the turn circuit working, however the turncircuit on the hauled trailer 83 is faulty, the tell tale monitor 84 isshowing this as no green turn LED is illuminated.

In FIG. 9 the hauling vehicle 85 this time has the brake circuitworking, the hauled trailer 86 also has the brake circuit working andthe tell tale monitor 87 is indicating that the trailer brake circuit isfunctioning correctly by illumination of the red brake LED. FIG. 10shows the hauling vehicle 88 with the brake circuit working and thehauled trailer 89 with the brake circuit not working and thus the telltale monitor 90 does not have the red brake LED illuminated. The haulingvehicle 91 in FIG. 11 has both brake circuit and electric brake circuitsoperating, the hauled trailer 92 also has both circuits operating, andthe tell tale monitor 93 is showing that the trailer circuits areoperating by illumination of the red brake LED and blue electric brakeLED. FIG. 12 however shows the hauling vehicle 94 with brake andelectric brake circuits working, however the hauled trailer 95 hasneither of the se circuits working, and thus the tell tale monitor 96 isshowing no illumination of either red brake or blue electric brake LEDs.FIG. 13 show the hauling vehicle 97 again, this time with the park lightcircuit operating. The hauled trailer 98 also has the park light circuitoperational, and this is being reported by the tell tale monitor 99 byillumination of the yellow park LED. FIG. 14 shows the hauling vehicle100 with the park light circuit on, in this case however the hauledtrailer 101 has a faulty park light circuit, and thus no yellow park LEDon the tell tale monitor 102 is illuminated.

With reference to FIG. 15 the mounting, and positioning of theelectrical tell tale system can be seen. The complete system is mountedsolely in the hauling vehicle 104 and no part or parts of the unit aremounted in the trailer at all 103. The tell tale monitor 105 is mountedon the dashboard anywhere where it looks neat and is practicable, thisis a unique design of the invention, flexibility. The tell tale monitor105 can easily be secured by Velcro tape and thus makes it easy to movewherever the driver desires. 106 is the modular cable which connects themonitor 105 to the main control unit 111. The modular cable 106 is runthrough the vehicle discreetly, under the trim. The wiring loom of thevehicle to the rear lights 107 has two main connections at the rear ofthe vehicle. 108 being the loom for the left hand side lights and 109being the connection for the trailer wiring loom. 110 is the connectionof the trailer signals into the main control unit 111 from the vehicleand 112 is the connection of the trailer signals out of the main controlunit 111 which go through the trailer plug 113 through the trailer loom115, to the trailer circuit wiring 115. The signals which pass throughthe main control unit 111 are not affected or impaired in any way whichwill affect the correct operation of the circuits on the trailer.Connection points 110 and 112 are can be universal or original equipmentmanufacture connectors for that particular vehicle. The mounting of thissystem is unique as the main control unit 110 requires no additionalpower source to be ran from the front of the vehicle to its position asit works of the wiring that's already there. The connection of themodular cable 106 from the main control unit 110 to the tell talemonitor 105 serves as a flexible and simple unique way of mounting thesystem.

In regard to FIG. 16 a driver's eye 123 and 127 is shown to define howthe system conveys its message. The hauling vehicle 116 towing thetrailer 117 has the right indicator on 120 and this indicator is alsoworking on the trailer 119 the main control unit in the trunk 118 issensing the correctness of this circuit and sending a signal through thevehicle 124 to the tell tale monitor 121 and 125 which illuminated 126and makes a visible sign to the drivers eye 123 and 127 that the rearcircuit on the trailer is functioning correctly. The illumination 126 ofthe tell tale monitor is just as noticeable in the day as in the night,so attention can be drawn to the drivers eye 123 and 127 any time thetrailer circuits are use providing that the tell tale monitor 121 and125 is mounted in a suitable and practicable position on or near thedash board of the vehicle.

FIG. 17 is the current load testing unit of the system. This device,incorporated with FIGS. 18 to 20 are used as diagnosis and testing toolsfor the tell tale system, FIG. 1. When the tell tale system, FIG. 1 isconnected to the vehicle, FIG. 15 the load testing unit, FIG. 17 isconnected to one of the voltage testing units, FIGS. 18 to 20 andapplies a load on all monitored circuits of the tell tale system, FIG.1, when those circuits are operated. This serves as an accurate testmeasure when finding faults or testing the system with no trailer. Thecurrent load tester is housed in a plastic box 128 which contains loaddevices such as bulbs or resistors and has three transparent lenses 129,130, 131 which illuminate when current is passed through the differentcircuits. 133 is a switch that changes the load voltage and thuscurrent. The switch can be slid down to 133 which will change the loadvoltage to 24 volts, the default position of the switch is for a loadvoltage of 12 volts. The current load testing unit 128 has a cablecoming out from its box 135 which is sheathed 7 core 4 mm cable that isdistributed and terminated at a male connector block 136. This maleconnector block 136 is designed to plug into 134, a female connectorblock of the voltage testing unit, FIG. 18. The voltage testing unit 137is a standard pre-manufactured 7 pin flat male type trailer connectorsuch as manufactured by the company Utilux. The unit has circuitryhoused inside the body and an array of light emitting diodes 138protruding out of the top of the unit. The voltage testing unit 137 isdesigned to plug into the trailer plug of the vehicle and test thevoltage of the various trailer circuits at the vehicles trailerconnector when those circuits are used. If the circuits voltage at thetrailer plug is correct, the correct LED will come illuminate, or abuzzer sound indicating that the voltage to that circuit is correct.Thus this testing unit is used in conjunction with the electrical telltale system to ensure that there is no fault in the trailer connectorbefore or after the tell tale system is installed or if a fault in thesystem is being diagnosed.

FIG. 19 shows a standard seven pin large trailer connector 139 and LEDarray 140, this is the same device as FIG. 18 however the actual plugtype is of a different standard, thus this unit can test a differenttype connector. FIG. 20 is again the same device as FIG. 18, howeverthis is a small seven pin round plug, again designed to test a differentstyle of trailer connector. FIG. 18 to 20 are all pre manufacturedstandard type trailer connectors which have been modified to form thecurrent testing devices.

The operation of the load current testing device and the voltage testingdevice for the tell tale system can be depicted from the schematic ofFIG. 21a The housing of the load device 143 consists of two load sets144 to 149 and 151 to 156. These load sets are for 12 and 24 volt loadswhich are selected by switch 165 which changes the main earth return164. The load sets 144 to 149 and 151 to 156 are either bulbs orresistors, which are set to the same load as the standard used on aparticular trailer circuit in real conditions.

150 and 157 are the earth returns for each load set. The two load sets144 to 149 and 151 to 156 are connected in parallel with each other atpoints 158 to 163. Diodes, 168 to 171 prevent any feed back throughother trailer circuits while a particular trailer circuit is beingtested. The load testing unit 143 is connected to the rear to thevoltage testing unit 172 by connector block 173, and connectionterminals 174 to 180. The voltage testing unit consists of a frontconnector 200 and connection pins 201 to 207 which conform tointernational standards for trailer connectors. Resistors 181 to 186limit the current of both 12 and 24 voltages to the unit, thusprotecting the light emitting diodes 189 to 192. These diodes aredifferent colours for each different trailer circuit and light when thecorrect voltage is passed through them indicating that the particulartrailer circuit is getting to the vehicles trailer connector. Theconnector block 173 of the voltage testing unit which is connected tothe load testing unit is connected in parallel with the LED circuit atpoints 193 to 199, this allows for both voltage and current to be testedat the same time when testing the tell tale system or diagnosing apossible fault with the system.

FIG. 21b is a second type of voltage testing unit 208, which tests thevoltage of the vehicles trailer connector the same way as 172 in FIG.21a, however this voltage testing unit 208 incorporates a buzzer 209 inits earth return 210 and thus conveys the correct voltage level whentesting by light as well as sound.

FIG. 22a shows the top view of the voltage testing unit 212 and its LEDarray 213 to 218. The circuits and colours defining the LED in the testunit 212 are, 213 left turn circuit, green, 214 stop circuit, red, 215auxiliary circuit one, white, 216 auxiliary circuit two, blue, 217 tailcircuit, yellow and 218 right turn circuit, green. These circuit andcolour configurations also apply to FIG. 23a, 224 to 227 and FIG. 24a231 to 236 in the respective ascending order as FIG. 22a, 213 to 218.FIG. 22b is the rear connector 211 of the voltage testing unit thatconnects with the current testing unit. The standard pin outconfiguration for this type of test unit is referenced at FIG. 22c whichshows the standard trailer wiring pin out and connector type 219 for thevoltage testing unit in FIG. 22a.

The circuits that correspond to the pin out connections for FIGS. 22c,23 c, 24 c in 219,228 and 237 respectively are as follows. 1 left turncircuit, 2 auxiliary one circuit, 3 earth return, 4 right turn circuit,5 auxiliary two circuit, 6, brake circuit, and 7 park circuit. FIG. 23ashows the a top view of the seven pin round large voltage testingconnector 220, and its position of the LED array 224 to 227, the rearconnector 211 of this voltage testing unit is shown in FIG. 23b whichconnects to the voltage testing unit, FIG. 17, and FIG. 23c shows thefront connector which conforms to the standard pin out as mentionedabove for this type of the voltage testing unit. FIG. 24a shows a topview of the small seven pin round voltage testing unit 230 and theposition of its LED array 231 to 236FIG. 24b shows the rear connector229 which connects to the load current testing unit as in FIG. 17 andFIG. 24c shows the pin out and wiring standard 237 for this type of thevoltage testing unit also mentioned above.

What is claimed is:
 1. An electrical tell tale system for trailercircuits that can be installed to a hauling vehicle having a trailerwiring, comprising: a) a main control unit having first and secondconnectors for being installed in series between the vehicles's trailerwiring and the trailer circuits; b) a tell tale monitor connected tosaid control unit and positioned in the vehicle to be visible to thedriver; c) said tell tale monitor including different colored lightemitting diodes, each color of said light emitting diodes recognizing aparticular trailer circuit to warn the driver of the vehicle of theoperating conditions of the trailer circuits; d) said control unitincluding a plurality of coils connected in series between said firstand second connectors such that each coil is connected in series betweenrespective trailer wiring and trailer circuit, such that the respectivecoil is energized when the respective trailer wiring and trailer circuitare energized; e) said control unit including a plurality of reedswitches, each switch being connected in parallel with a respective coilsuch that said switch is activated when its respective coil isenergized, each switch being connected to a respective diode to activatethe respective diode when the respective coil is energized to inform thedriver that the respective trailer circuit is operating; f) said controlunit including a plurality of resistors each of which is connected inseries with a respective reed switch to limit the current through saidswitch in case of a short; and g) said first and second connectors areconfigured such that said first and second connectors may be reverselyconnected to the vehicle's trailer wiring and the trailer circuitswithout affecting the operation of the system.
 2. An electrical telltale system as in claim 1, wherein said monitor is remote from saidcontrol unit.
 3. An electrical tell tale system as in claim 1, whereineach of said switches operates intermittently when activated if anincorrect wattage globe is used in a respective trailer circuit, therebycausing the respective light emitting diode to flash.
 4. An electricaltell tale system as in claim 1, wherein each of said reed switches isdisposed within a respective coil.
 5. An electrical tell tale system asin claim 1, wherein said main control unit is sealed in a plastichousing, filled with epoxy resin.
 6. An electrical tell tale system asin claim 1, wherein said control unit includes a modular socket forconnection to a modular plug carried by said tell tale monitor.
 7. Anelectrical tell tale system as in claim 1, wherein said connectors areconnector blocks.
 8. An electrical tell tale system as in claim 1,wherein said different colored diodes are blue, red, yellow and green.9. An electrical tell tale system as in claim 8, wherein: a) saidtrailer circuits include an electric brake circuit; and b) said bluediode indicates the condition of said electric brake circuit.
 10. Anelectrical tell tale system as in claim 8, wherein: a) said trailercircuits include a brake lights circuit; and b) said red diode indicatesthe condition of said brake lights circuit.
 11. An electrical tell talesystem as in claim 8, wherein: a) said trailer circuits include a turnindicator circuit; and b) said green diode indicates the condition ofsaid turn indicator circuit.
 12. An electrical tell tale system as inclaim 8, wherein: a) said trailer circuits include a parking lightcircuit; and b) said yellow diode indicates the condition of saidparking light circuit.
 13. An electrical tell tale system as in claim 1,wherein said tell tale monitor includes a buzzer.
 14. An electrical telltale system as in claim 1, wherein said tell tale monitor is compactsuch as to be easily mounted anywhere in the vehicle in view of thedriver.
 15. An electrical tell tale system as in claim 1, wherein saidlight emitting diodes are visible day or night.